Research Article
Deflection-stiffness Relationship and Practical Implications for Seismic and Wind Imposed Design of Tall Steel Buildings
Vijay Kumar Khanna*
Issue:
Volume 14, Issue 1, February 2026
Pages:
1-10
Received:
23 November 2025
Accepted:
20 December 2025
Published:
16 January 2026
Abstract: Tall steel buildings are increasingly governed by serviceability considerations arising from seismic and wind actions, where control of lateral deflection and inter-storey drift becomes as critical as strength-based design. This paper investigates the fundamental relationship between lateral stiffness and deflection response in tall steel structures, with the objective of clarifying the role of stiffness in satisfying codal requirements for safety, serviceability, and occupant comfort. A common misconception in design practice is that increased structural flexibility invariably leads to reduced seismic demand. While period elongation associated with reduced stiffness may lower seismic base shear, it can result in excessive lateral deflections, inter-storey drifts, and wind-induced accelerations that govern serviceability performance. Using a shear-building idealisation, closed-form analytical relationships are developed to link effective lateral stiffness, fundamental natural period, inter-storey drift, and seismic base shear. Three representative lateral load-resisting systems-a steel moment-resisting frame (SMRF), a braced frame (BRBF), and a core-outrigger system-are evaluated for a 20-storey steel building to illustrate the influence of stiffness on global and local response parameters. The comparative results demonstrate that increased stiffness leads to improved drift control and wind-serviceability performance, even where seismic base shear increases modestly. A worked example is presented to demonstrate drift verification against Eurocode seismic serviceability limits and wind habitability criteria, showing that serviceability requirements often govern system selection in tall buildings. The study provides practical guidance on balancing stiffness, damping, and structural configuration during preliminary design. The proposed analytical framework supports rational comparison of alternative lateral systems and offers useful insights for engineers prior to undertaking detailed numerical analysis.
Abstract: Tall steel buildings are increasingly governed by serviceability considerations arising from seismic and wind actions, where control of lateral deflection and inter-storey drift becomes as critical as strength-based design. This paper investigates the fundamental relationship between lateral stiffness and deflection response in tall steel structure...
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Research Article
Optimization of Asphalt Concrete Performance Using Waste Plastic Bottles (WPB) as a Sustainable Bitumen Modifier:
A Comprehensive Rheological and Mechanical Assessment
Issue:
Volume 14, Issue 1, February 2026
Pages:
11-19
Received:
9 January 2026
Accepted:
19 January 2026
Published:
30 January 2026
DOI:
10.11648/j.ajce.20261401.12
Downloads:
Views:
Abstract: This study investigated the potential of utilizing Waste Plastic Bottles (WPB) as a sustainable modifier in asphalt pavement mixtures, systematically examining the characteristics of aggregates, the WPB-modified bitumen binder, and the resulting asphaltic concrete mix. Detailed analysis of the aggregate gradation revealed the coarse fraction to be a well-graded gravel, characterized by a uniformity coefficient (Cu) of 2.47 and coefficient of curvature (Cc) of 1.14, indicative of optimal packing density for structural stability. These aggregates exhibited high durability, with an Aggregate Crushing Value (ACV) of 18.3% and Aggregate Impact Value (AIV) of 16.9%, ensuring resistance to abrasion and impact under traffic loads. In contrast, the fine aggregate was poorly graded (Cc = 0.45), highlighting the need for binder modification to enhance overall mix cohesion. Modification of pure bitumen (initial penetration 69 mm) with WPB progressively induced desirable hardening effects and superior high-temperature performance. Penetration values decreased markedly from 69 mm to 33 mm at 25% WPB incorporation, while the softening point rose substantially from 52°C to 81°C, demonstrating enhanced rutting resistance and thermal stability critical for tropical climates like Nigeria's Lagos region. Additional rheological improvements included increased viscosity (up to 2984 p.a.s), flash point (289°C), and specific gravity (1.13), with minimal ductility loss, collectively affirming WPB's role in creating a more resilient binder. Marshall performance testing on the WPB-modified asphaltic concrete further validated these enhancements. The mixture achieved maximum Marshall Stability of 19.74 kN and peak Marshall Quotient of 4.32 kN/mm at 15% WPB content— a 78% stability increase and 34% quotient gain over the control mix (11.05 kN and 3.22 kN/mm). Flow values remained controlled (3.43–4.57 mm), balancing stiffness with workability. These outcomes, aligned with prior pelletized WPB concrete data showing optimal 10–15% thresholds, confirm WPB's efficacy in boosting stiffness, load-bearing capacity, and deformation resistance. Overall, WPB modification yields a mechanically superior, eco-friendly alternative to conventional asphalt, promoting waste valorization while meeting geotechnical standards for durable pavements in sustainable infrastructure projects.
Abstract: This study investigated the potential of utilizing Waste Plastic Bottles (WPB) as a sustainable modifier in asphalt pavement mixtures, systematically examining the characteristics of aggregates, the WPB-modified bitumen binder, and the resulting asphaltic concrete mix. Detailed analysis of the aggregate gradation revealed the coarse fraction to be ...
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Research Article
Seismic Performance Evaluation of a 10-story RC Building Using Pushover Analysis & Response Spectrum Analysis
Issue:
Volume 14, Issue 1, February 2026
Pages:
20-38
Received:
8 January 2026
Accepted:
20 January 2026
Published:
31 January 2026
DOI:
10.11648/j.ajce.20261401.13
Downloads:
Views:
Abstract: Seismic performance evaluation of high-rise buildings plays a crucial role in maintaining structural safety within earthquake-prone regions. The growing frequency and intensity of seismic activities worldwide require innovative approaches to structural design that focus on resilience, creating sustainable solutions and safety assurance. The conventional force-based methods fail to properly capture nonlinear structural behaviors. On the other hand, energy-based seismic analysis provides a better understanding of how seismic energy get absorbed and distributed within buildings that is to say, the pathways through which earthquake energy flows. This study analyzes the behavior of a 10-story reinforced concrete (RC) building using pushover analysis (POA) and response spectrum analysis (RSA) in ETABS, following the Bangladesh National Building Code (BNBC 2020). The building is modeled with typical gravity and lateral load-resisting systems, considering BNBC seismic code specifications. The POA provides insights into the nonlinear performance of the structure, identifying hinge locations and performance levels under increasing lateral loads. Meanwhile, RSA assesses building responses to seismic motions through vibration pattern studies. A comparative evaluation of base shear, story displacement and drift ratios is conducted to determine whether the structure meets BNBC safety limits. Results suggest that while response spectrum analysis is effective for preliminary design, pushover analysis offers deeper insight into potential failure mechanisms. This study emphasizes the significance of integrating both static and dynamic approaches for a comprehensive seismic evaluation of high-rise buildings.
Abstract: Seismic performance evaluation of high-rise buildings plays a crucial role in maintaining structural safety within earthquake-prone regions. The growing frequency and intensity of seismic activities worldwide require innovative approaches to structural design that focus on resilience, creating sustainable solutions and safety assurance. The convent...
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